1. Field of the Invention
The present invention relates to a lock system that locks and unlocks functions of various apparatuses such as a cellular phone, and the present invention particularly relates to a lock system, an unlock device, various apparatuses such as a portable terminal device, an unlock method, an unlock program, and a circuit device that unlock a lock with an unlock signal.
2. Description of the Related Art
Measures are taken by installing a dial lock function to a cellular phone to prevent an unauthorized use by someone else and to retain confidentiality such as directory data of the phone. When the dial lock is set, the dial lock function requires such an operation as password inputting and prevents unlocking by someone else.
The lock functions are disclosed in Japanese Patent Application Laid-Open Publication Nos. 2001-245354, 2000-165511, 2003-289307, H09(1997)-98488, and H09(1997)-64967. In Japanese Patent Application Laid-Open Publication No. 2001-245354, a cellular phone transmits an unlock code to an unlock device by a weak electric wave. The unlock device transmits to the cellular phone a result of identification calculation conducted with the unlock code and ID information, and locked state of the cellular phone is unlocked based on the result of the identification calculation.
In Japanese Patent Application Laid-Open Publication No. 2000-165511, a voice recognition function is installed on a cellular phone, and the cellular phone recognizes a user's voice signal from a distant place and sets or unlocks a dial lock.
In Japanese Patent Application Laid-Open Publication No. 2003-289307, communications among apparatuses within a communication range is allowed, and when any one of the apparatuses deviates from the communication range, communications of all the apparatuses are automatically locked. When the apparatus out of the communication range comes back to the communication range, communications of the apparatuses are unlocked.
In Japanese Patent Application Laid-Open Publication No. H09 (1997)-98488 a cellular phone receives lock control information that is transmitted externally by an infrared ray. The cellular phone locks or unlocks a lock based on a situation judgment of the cellular phone and the lock control information.
In Japanese Patent Application Laid-Open Publication No. H09 (1997)-6496V, an unlock device dial-locks or unlocks a cellular phone. After unlocking, when the cellular phone cannot receive a code from the unlock device for a certain time, dial lock is set.
As mentioned above, a lock system uses a wireless signal to set a lock or unlock of apparatuses such as a cellular phone. However, when communications of the same time cycle or wireless signals of the same frequency are conducted, a plurality of wireless signals travel among adjacent people at workplaces and offices or in trains, etc. Communications may become impossible as a result of electromagnetic interference such as radio wave interference, and wireless signals may not be received correctly. It is inconvenient that locking and unlocking are unable to be conducted.
No disclosures or suggestions of the problem are provided in Japanese Patent Application Laid-Open Publication Nos. 2001-245354, 2000-165511, 2003-289307, H09 (1997)-98488, and H09 (1997)-64967, and no configurations to solve the problem are disclosed or suggested.